Mechanical properties of silver sintered bond lines: Aspects for a reliable material data base for numerical simulations

This paper deals with the characterization of mechanical material properties of silver sintered bond lines in power electronic modules. Two different methods for obtaining the mechanical properties were applied. Silver sintered specimens were manufactured for both tensile and nanoindentation experiments. The manufacturing procedure was the same as for the silver sintering process in die attachment for power electronics. In tensile tests the specimens showed at room temperature brittle behaviour whereas at elevated temperature large ideal plastic deformation with reduced Young's modulus could be observed. The mechanical properties are depending strongly on sintering parameters and on the whole manufacturing process. By combination of nanoindentation and scanning electron microscopy it could be revealed that the properties of the bond lines depending strongly on its location on the sample. The investigation of the time dependent behavior showed small values and little dependency of the porosity at room temperature.